Movable drain connection for humidifier sump



"Dec; 30.v 1969 D. MULLINGSY 3,486,523

MOVABLE DRAIN CONNECTION FOR HUMIDIFIER SUMP Filed July 5, 1967 F 2. H63E::I I I 2| INVENTOR. DONALD M. MULLJ N65 HlS ATTORNEY United StatesPatent O 3,486,523 MOVABLE DRAIN CONNECTION FOR HUMIDIFIER SUMP DonaldM. Mullings, Yardley, Pa., assignor to General Electric Company, acorporation of New York Filed July 3, 1967, Ser. No. 650,977 Int. Cl.F24f 3/14; F16] 5/00 U.S. Cl. 137-271 4 Claims ABSTRACT OF THEDISCLOSURE A container or sump of a humidifier for use in the hot airduct of a hot air up-flow furnace heating system where the sump isprovided with alternate drain holes in the bottom and side wallsthereof. The installer of the humidifier is given the opportunity ofmounting the humidifier either to the underside of the duct or to thevertical side of the duct, as well as to make an over flow drainconnection through one of several, alternate drain holes. This inventionrelates to an easily assembled and disassembled drain connectioncomprising a resilient grommet located in and sealed to the edge of oneof the holes of the Walls of the sump, and a tubular member extendingthrough and in sealed relationship with the grommet. A furtherimprovement is forming the inlet edge of the tubular member at anupwardly inclined angle so that the flow will be concentrated at thelowest point of the inlet edge and the velocity of the flow will be at amaximum.

BACKGROUND OF THE INVENTION There are many deleterious effects resultingfrom heating occupied spaces or buildings with forced hot air that hasnot been humidified. For example, dry, heated air recirculating throughthe furnace system absorbs moisture from the nose and throat areas ofthe occupants of the building resulting in discomfort, restrictedbreathing passages, chronic coughing and insomnia. In addition, dry airevaporates moisture from the human body causing the body to feel cooland chilly even through the temperature is relatively high. Since dryair requires higher temperatures for comfort than does humidified air,there is also a substantial increase in expenditures for fuel requiredto heat comfortably with non-humidified air.

These deleterious effects are avoided by installing a humidifier in thehot air distribution duct or furance plenum of the heating system. Themain elements of a furnace humidifier are a power driven air handlingdevice, and evaporating elements means for wetting the element so thatthe hot air is caused to pass through the element and pick up apercentage of the moisture from the element before the hot air proceedsthrough the distribution duct. A humidifier is customarily wired from asource of electrical power in a manner to operate only when the arm airfurnace blower is running. A humidistat is furnished with the humidifierand it controls an electrically operated water valve that supplies waterto the humidifier. This water is fed to a water distributor for anevaporating element. This element is a wettable filter pad having highsurface area through which the hot furnace air can Patented Dec. 30,1969 "ice be drawn. An electric fan or blower provides the air movingfunction through the evaporating element. A slight amount of excesswater is allowed to drain from the ele ment and accumulate in a sump andto be removed through the drain connection of the present invention.This continuous draining or flushing action tends to keep mineralconcentrations down by allowing them to be washed away by the flowinstead of collecting on the internal parts of the humidifier.

Difficulties have been experienced during the installation of thesehumidifiers due to the cramped working conditions in certain furnaceareas which makes it difficult to make a universal design of humidifierfor many sets of conditions for bringing in the electrical power, thewater supply as well as making the drain connection for accommodatingthe water overflow. Sometimes the humidifier can only be mounted on theunderside of the duct and other times it has to be mounted on thevertical side of the duct and these conditions require specialconsideration.

SUMMARY OF THE INVENTION The present invention, is accordance with oneform thereof, relates to the sump of a humidifier or broadly a liquidcontainer having a bottom wall and raised side walls. There arealternate drain holes formed in the walls of the sump as well as meansfor closing the drain holes. A drain connection is formed through one ofthe holes and it includes a resilient grommet fastened in the hole and atubular member extending through the grommet and sealed with respect tothe grommet while the grommet is sealed with respect to the edge of thehole. A further improvement is to form the upper end of the tubularmember with a funnel shape which has an inlet edge formed at an inclinedangle whereby the drain flow will be concentrated at the lowest point ofthe inlet edge and the velocity of the water flow will be at a maximum.

BRIEF DESCRIPTION OF THE DRAWINGS My invention will be better understoodfrom the following description taken in conjunction with theaccompanying drawing and its scope Will be pointed out in the appendedclaims.

FIGURE 1 is a perspective view of a liquid container such as the sump ofa furnace humidifier showing alternate drain holes in the bottom walland the side wall of the sump.

FIGURE 2 is an elevational view of a humidifier housing containing thealternate drain hole arrangement of FIGURE 1.

FIGURE 3 is a fragmentary detailed view taken on the line 33 of FIGURE 2and showing the means for closing the drain holes until one of them ischosen, by using knock-outs which are formed by scoring the housingwall.

FIGURE 4 is a fragmentary, cross-sectional, elevational view on anenlarged scale taken through the center of one of the drain holes in thebottom wall of the container having a drain connection of the presentinvention mounted therein.

FIGURE 5 is a view similar to FIGURE 4 of a second modification of thepresent invention showing the upper end of the tubular member of thedrain connection with an inlet edge formed at an upwardly inclined angleso that the flow is concentrated at the lowest portion of the inletedge.

DESCRIPTION OF THE PREFERRED EMBODIMENT Turning now to a considerationof the drawings and in particular to FIGURE 1 there is shown a box-likecontainer of metal or plastic material for forming a drain pan or sumpof a furnace humidifier and it has a bottom wall 11 and raised sidewalls 12. A plurality of alternate drain holes 13, 14 and 15 are formedin the walls of the container for ease in making a drain connection withthe container depending on how the humidifier is mounted to a hot airdistribution duct. In some installations the drain can extend from thebottom wall 11, but in others the humidifier must be turned on its sideand the drain extend through side hole 15. These drain holes 13, 14 and15 are normally closed by a knock-out 17 as is best seen in FIGURE 3. Ofcourse, an alternative would be to close the holes with rubber caps orplugs. Each knockout is formed by scoring the wall of the container in acircular pattern as at 19. This scoring substantially outlines theconfiguration of the knock-out, and a slight blow with a hammer orchisel will cause the knock-out to become disengaged from the wall andthereby create the proper drain hole.

Turning now to a consideration of FIGURE 4, it is noticed that the drainhole 13 is indented in the bottom wall 11 of the drain pan by means ofan embossment 21. Many local plumbing codes require a metal tube ornipple for making fixed plumbing connections. The drain connectioncomprises a resilient grommet 23 that is adapted to be fastened in thedrain hole 13, as well as a tubular member 25 that is adapted to extendthrough the grommet. The grommet is made of a rubber material such asneoprene or the like, and it is formed with a central opening 27 and aperipheral groove 29 which is adapted to receive the peripheral edge ofthe drain hole 13. The relative size of the groove 29 and the resiliencyof the grommet is such that the groove embraces the peripheral edge ofthe hole 13 and provides a water tight seal.

The central opening 27 in the grommet is of a diameter slightly smallerthan the diameter of the tubular member 25 so that there is a force fitbetween the tubular member and the opening which likewise creates asealing action therebetween. The upper end of the tubular member 25 isformed in a conical or funnel shape 31 which is seated against the topof the grommet. The modification of FIGURE 4 shows a push nut 33 ofspring material forced over the lower end of tubular member 25 and intoengagement with the underside of the grommet to cooperate with theenlarged upper end 31 of the tubular member and exert a compressiveforce against the grommet to provide a liquid sealing action as well asto prevent relative displacement of the parts during the use of thehumidifier when vibrations might be set up by the furnace blower orhumidifier fan and tend to cause the tubular member to become dislocatedin the grommet. Notice that a drain hose 35 of flexible material isinstalled over the lower end of the tubular member 25 for carrying offthe drain flow.

Although distilled water would be ideal, or any water containing nomineral deposits, tap water is naturally used in a furnace humidifierbecause of its convenience and economy. Furthermore, the water beingcirculated over the evaporating element may remove additional foreignmatter from the air so that during the heating season several pounds ofscale-forming material may collect in the humidifier system.

Since the drain connection of the present invention is a low water flowdevice calcium deposits accumulate on the evaporating element as well ason the walls forming the sump and they tend to clog the passagewaysespecially in the vicinity of the drain connection. The

reason for this clogging is the tendency for sediment and residues ofthe evaporation process to collect in a slimelike material around theinlet to the drain connection. The runoff is slow when the inlet edge ofthe tubular member 25 is cut square in a horizontal plane since the flowextends completely around the inlet edge for 360. Slime or scale willbuild up at this point of low velocity, possibly to the extenteventually clogging the entire drain inlet.

One important way to reduce this accumulation of slime and scale is toincrease the velocity of flow. This can be done without changing thevolume of fiow by making the change shown in the second modification ofFIGURE 5, where the inlet edge 37 of the funnel shaped upper end 31 ofthe tubular member 25 is cut at a raised angle of 10 to 40 above thehorizontal, and preferably of approximately 20 to 30 above thehorizontal, so as to cause all of the flow to occur at the lowest point;namely, at point 39 as shown in FIGURE 5. This technique is much betterthan cutting a small notch in the inlet edgeof the drain tube becausethis notch would be subject to clogging by small floating particles. Ifforeign material should accumulate at the low point 39, the flow wouldsplit and proceed around the sides of the foreign material tending toundercut and free the offending particles.

Having described above my invention of a drain connection for a liquidcontainer having a low flow characteristic it will readily be apparentto those skilled in this art that I have provided an easy fieldselection of alternate drain points for the convenience of theinstaller, plus a vibration isolating system has been formed between thecontainer 10 and the drain tube 35 by means of the resilient grommet, aswell as providing a successful liquid sealing arrangement between thecontainer and the grommet and the grommet and the tubular member 25 sothat the fiow is confined by the drain connection, and finally means areprovided to increase the velocity of the flow through the drainconnection without increasing,

the volume of the flow so as to provide a proper flushing action andreduce the rate of sediment, scale and slime buildup within thehumidifier system.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. In a liquid container having a bottom wall and raised side walls, adrain connection formed in said bottom wall and comprising a hole formedin the bottom wall, a resilient grommet fastened in said hole, thegrommet having a central opening as well as a pheripheral groove forreceiving the peripheral edge of the hole, and a tubular member ofslightly larger size than the grommet opening extending through saidopening, the upper end of the tubular member being of funnel shape andin engagement with the grommet, said funnel shaped upper end of thetubular member having an inlet edge formed at a raised inclined plane ofbetween about 10 and about 40 whereby the inlet flow will be at thelowest point of the inlet edge and the velocity of the liquid flow intothe tubular member will be at a maximum.

2. A humidifier sump having a bottom wall and raised side walls forcontaining water therein, alternate drain holes formed in the bottomwall and in the side walls, means for closing the drain holes, a drainconnection formed through one of the holes and comprising a resilientgrommet fastened in a hole through the bottom wall, the grommet having acentral opening therethrough and peripheral means for sealing thegrommet to the peripheral edge of the hole, a tubular member extendingthrough the grommet opening, the upper end of the tubular member beingenlarged and seated on said grommet, and a push nut forced over thelower end of the tubular member and against the grommet to exert incooperation with the enlarged upper end of the tubular member acompressive force on the grommet.

3. A humidifier sump as recited in claim 2 wherein the 5 enlarged upperend of the tubular member is of funnel shape which has an inlet edgeformed at an inclined angle whereby the drain flow will be concentratedat the lowest point of the inlet edge and the velocity of the water flowwill be at a maximum.

4. A humidifier sump as recited in claim 3 wherein the peripheral meansfor sealing the grommet comprises a continuous groove extending aroundthe grommet for receiving the peripheral edge of the hole.

References Cited UNITED STATES PATENTS 709,395 971902 Cook 137-356 XR 62/ 1959 Boyer 285208 XR 1/1963 Main 137271 XR 1/1963 Tidd 137271 XR7/1966 Cipriano 137271 XR FOREIGN PATENTS 3 1961 Germany.

M. CARY NELSON, Primary Examiner 10 R. J. MILLER, Assistant Examiner US.Cl. X.R.

